1. Field of the Invention
There is a continuing need to control weeds which interfere with the growth, maintenance and harvesting of crops. The Italian thistle which is endogenous to the Mediterranean area is now also found in California and environs. The Italian thistle is a major weed pest, occurring in pasture, range land and ruderal areas and is especially a problem in grazing areas where dense stands cause eye injury to cattle. In addition, its presence in orchards or farmland, can interfere with the maintenance and harvesting of crops.
It is therefore desirable to provide an inexpensive, safe and ecologically acceptable way for inhibiting the growth of thistle, without harming other desirable crops or grasses.
2. Description of the Prior Art
Walker and others have reported that A. macrospora, A. cassiae and A. sp. are phytopathogenic to spurred anoda, sicklepod and leafy spurge, respectively. See Walker, Weed Science (1981) 29:505-507; Walker, ibid (1981) 29:629-631; and Walker and Riley, ibid (1982) 30:651-654. See also, Krupinsky and Lorenz, ibid (1983) 31:86-88. A method of growing spores is described by Walker, (1980) USDA Science and Education Administration Advanced Agricultural Federal Bulletin Southern Series. ISSN 01923-3728 No. 12.